Testicular Spermatozoa Are of Better Quality Than Epididymal Spermatozoa in Patients With Obstructive Azoospermia

Reproductive outcomes after surgical sperm retrieval in couples with male factor subfertility: a 10-year retrospective national cohort

OBJECTIVE

To determine any significant differences in the reproductive outcome from intracytoplasmic sperm injection (ICSI) with surgical sperm retrieval (SSR) between cycles using fresh and cryopreserved sperm and between cycles using epididymal and testicular sperm.

DESIGN

A retrospective national cohort study using data from the UK Human Fertilisation and Embryology Authority, including all ICSI cycles performed in the United Kingdom over a 10-year period.

SETTING

Hospital.

PATIENT(S)

All nondonor ICSI cycles from 2008 to 2017 categorized by sperm source and cryopreservation status.

INTERVENTION(S)

Intracytoplasmic sperm injection with SSR using fresh or cryopreserved sperm and using ejaculated, testicular, and epididymal sperm.

MAIN OUTCOME MEASURE(S)

Live birth rate, pregnancy rate, and implantation rate.

RESULT(S)

We analyzed data from 214,649 ICSI cycles, including 199,818 cycles of ejaculated sperm, 5,646 cycles of epididymal sperm, and 9,185 cycles of testicular sperm. Live births rates per ICSI cycle were 28.5%, 30.6%, and 28.7% for ejaculated, epididymal, and testicular sperm cycles, respectively. Epididymal sperm cycles had a higher live birth rate than that of testicular sperm cycles (odds ratio [OR], 1.067; 95% confidence interval [CI], 1.014-1.123). This was despite a higher mean male age (42.5 vs. 40.6 years; 95% CI of difference, 1.81-1.85 years) and female age (34.3 vs. 34.0 years; 95% CI of difference, 0.32-0.34 years) in epididymal cycles than in testicular cycles. Implantation (61.2% vs. 58.0%; OR, 1.086; 95% CI, 1.041-1.133) and clinical pregnancy rates (34.3% vs. 31.3%; OR, 1.085; 95% CI, 1.039-1.132) were also higher in epididymal cycles than in testicular cycles. There were no statistically significant differences in outcomes between cycles using fresh sperm and those using cryopreserved sperm for SSR-ICSI.

CONCLUSION(S)

Our study indicates that reproductive outcomes of SSR-ICSI are at least comparable with those of ICSI using ejaculated sperm and does not support the preferential use of fresh sperm over cryopreserved sperm in SSR-ICSI. Births per SSR-ICSI cycle were higher for cycles using epididymal sperm than for cycles using testicular sperm; however, the differences were small, which may provide reassurance to patients undergoing these procedures. The results must be interpreted with caution because multivariable analysis was not possible because of aggregation of data.

Are testicular sperms superior to ejaculated sperms in couples with previous ART failure due to high rate of fragmented embryos? A retrospective cohort study

Objective

The aim was to clarify whether using testicular sperm reduces embryo fragmentation and improves cycle outcomes.

Methods

Fragmented embryo was defined as an embryo in which fragments account for more than one third of the embryonic surface area. High rate of fragmented embryos was defined by a proportion of fragmented embryos higher than 50%. We recruited infertile couples who had undergone at least one ovarian stimulation cycle using ejaculated sperm but failed to conceive due to high rate of fragmented embryos in each previous cycle. After fully informed consent, the couples agreed to obtain testicular sperm by testicular puncture and use testicular sperm for intracytoplasmic sperm injection (ICSI). The normal fertilization rate, transferable embryo rate, fragmented embryo rate and cycle outcomes were compared between ejaculated sperm group (EJA-sperm group) and testicular sperm group (TESTI-sperm group).

Results

Twenty-two couples who agreed to participate in our study underwent 32 ICSI cycles with ejaculated spermatozoa and 23 ICSI cycles with testicular spermatozoa. Embryo transfers were cancelled in 8 ejaculated cycles and 4 testicular cycles because of no transferable embryos. There were no significant differences in age, normal fertilization rate and high-quality embryo rate between ejaculated and testicular groups. The transferable embryo rate and implantation rate in TESTI-sperm group were significantly higher than those in EJA-sperm group (36.9% vs. 22.0%, p < 0.01; 34.2% vs. 0%, p < 0.001). The fragmented embryo rate in TESTI-sperm group was significantly lower than that in EJA-sperm group (61.2% vs. 75.7%, p < 0.05).

Conclusion

Our small retrospective cohort study suggests that using testicular sperm may be a recommended option for couples with previous ART failure because of high rate of fragmented embryos. Large samples, multicenter studies or randomized controlled trial (RCT) are needed to further confirm the superiority of testicular sperm.

Modern surgical treatment of azoospermia

PURPOSE OF REVIEW

To review noteworthy research from the last 2 years on surgical management of azoospermia.

RECENT FINDINGS

The recommended treatments for nonobstructive and obstructive azoospermia have not appreciably changed. However, recent level-1 evidence has reinforced superiority of micro-dissection testicular sperm extraction over sperm aspiration in men with nonobstructive azoospermia, and several studies have identified genetic and other clinical factors that may aid in selecting candidates for testicular sperm extraction. Machine learning technology has shown promise as a decision support system for patient selection prior to sperm retrieval as well a tool to aid in sperm identification from testis tissue.

SUMMARY

Most men with obstructive azoospermia who desire fertility can be offered either surgical reconstruction or sperm retrieval. For men with nonobstructive azoospermia, sperm retrieval with microdissection testicular sperm extraction remains the gold standard treatment. Uncovering more genetic causes of nonobstructive azoospermia may aid in properly counseling and selecting patients for microdissection testicular sperm extraction. Neural networks and deep learning may have a future role in patient selection for surgical sperm retrieval and postprocedural sperm identification.

The developmental miR-17-92 cluster and the Sfmbt2 miRNA cluster cannot rescue the abnormal embryonic development generated using obstructive epididymal environment-producing sperm in C57BL/6 J mice

BACKGROUND

Sperm, during epididymal transit, acquires microRNAs(miRNAs), which are crucial for embryonic development. However, whether sperm miRNAs influenced by an obstructive epididymal environment affect embryonic development remains unknown.

METHOD

The sham operation and vasectomy were performed in C57BL/6 J mice to create the control group (CON) and the obstructive epididymal environment group(OEE) group, respectively. The morphology of the testis and epididymis was observed using hematoxylin and eosin staining (HE staining) to establish the OEE mice model. The sperm quality test, intracytoplasmic sperm injection (ICSI), and epididymosomes fusion were employed to observe the effect of the obstructive epididymal environment on sperm and resultant embryonic development. The alteration of the sperm small RNA (sRNA) profile was analyzed by sRNA sequencing. RT-qPCR and DNA methylation were applied to observe the effect of obstructive epididymis on the expression of sperm miRNAs. The miRNAs microinjection was used to explore the impacts of sperm miRNAs on embryonic development.

RESULTS

We confirmed postoperative 8-week mice as the OEE mice model by examining the morphology of the testis and epididymis. In the OEE group, we observed that sperm quality degraded and the development potential of embryos was reduced, which can be saved by the normal epididymal environment. The sperm sRNA sequencing revealed that the expression of the developmental miR-17-92 cluster and the Sfmbt2 miRNA cluster was downregulated in the OEE group. The expression of these two miRNA clusters in epididymis was also downregulated and regulated by DNA methylation. However, the downregulation of either the miR-17-92 cluster or the Sfmbt2 miRNA cluster in normal zygotes did not impair embryonic development.

CONCLUSION

The obstructive epididymal environment influences sperm quality and resultant embryonic development, as well as the abundance of the developmental miR-17-92 cluster and the Sfmbt2 miRNA cluster in sperm, but these miRNA clusters are not the cause of abnormal embryonic development. It implies that epididymis is important in early embryonic development and may play a potential role in sperm epigenome.

Sperm degradation after vasectomy follows a sperm chromatin fragmentation dependent mechanism causing DNA breaks in the toroid linker regions

Vasectomy is a widely used surgical technique creating an obstructive azoospermia. Although sperm cannot be ejaculated, the testis maintains sperm production in vasectomized males. The continuous accumulation of sperm deposited in the epididymis and the vas deferens fraction necessarily need to be degraded and eliminated. While the elimination process is carried out by granulomas that form after vasectomy, the detailed mechanisms of sperm degradation are still not known. The aim was to assess whether sperm chromatin fragmentation (SCF), a mechanism that degrades the entire sperm genome at the toroid linker regions (TLRs), is activated after vasectomy in sperm cells. We vasectomized mice and evaluated the presence of TLR-specific double-strand breaks through pulsed-field gel electrophoresis and the Comet assay at 1, 2 and 3 weeks after surgery. Results for DNA damage (Olive tail moment) at single-cell level showed an increase of double-strand breaks after vasectomy for vas deferens sperm after 1, 2 and 3 weeks postvasectomy (21.78 ± 2.29; 19.71 ± 1.79 and 32.59 ± 1.81, respectively), compared to mock surgery (7.04 ± 1.03; 10.10 ± 1.29 and 8.64 ± 0.85, respectively; P < 0.001). Similar findings were obtained for cauda epididymis sperm (P < 0.001), but not for caput epididymis (P > 0.05). Pulsed-field gel electrophoresis showed the presence of double-stranded breaks between 15 and 145 kb, indicating that DNA breaks were produced mainly in the sperm TLRs. Results presented here suggest that SCF is a mechanism activated in vas deferens after vasectomy to degrade sperm DNA when they cannot be ejaculated, preventing their function.

TESE-ICSI outcomes per couple in vasectomized males are negatively affected by time since the intervention, but not other comorbidities

RESEARCH QUESTION

Does time since vasectomy (as obstructive interval) and the presence of different male comorbidities adversely affect the likelihood of achieving a newborn for vasectomized males undergoing testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI)?

DESIGN

This retrospective study included 364 couples with vasectomized males undergoing TESE-ICSI cycles with autologous oocytes at IVI Valencia. The main outcome was live birth rate (LBR). Subjects were divided according to the male risk factor evaluated into quartiles (obstructive interval, body mass index [BMI]) or groups (hypertension, diabetes mellitus, dyslipidaemia). The reproductive outcomes were calculated per embryo transfer, per ovarian stimulation completed, and per couple.

RESULTS

The average obstructive interval was 11.3 years. The LBR was 34.4% (95% CI 30.1-38.6) per embryo transfer, 27.8% (95% CI 24.1-31.5) per ovarian stimulation and 46.2% (95% CI 41.8-51.3) per couple. When considering obstructive interval, a significantly lower LBR per couple (P = 0.04) was found in the group with the longest obstruction time: Q1 42.1% (95% CI 33.5-50.7), Q2 49.1% (95% CI 36.1-62.1), Q3 56.3% (95% CI 46.7-65.9) and Q4 37.2% (95% CI 26.5-47.9) but the cumulative live birth rate (CLBR) was not affected (P = 0.63). LBR per ovarian stimulation of males with hypertension was significantly lower (P = 0.04) than healthy males: 13.5% (95% CI 2.5-24.5) and 28.6% (95% CI 24.7-32.5), respectively. The group of diabetic vasectomized males had a significantly higher CLBR (P = 0.02). The remaining risk factors assessed (smoking, dyslipidaemia and a high BMI) did not affect LBR compared with their healthy counterparts.

CONCLUSION

Time since vasectomy appears to negatively influence the LBR when assessed per couple. The CLBR was not affected by the obstructive interval or the presence of other male comorbidities apart from diabetes, which had a significant effect.

Does acquired obstructive azoospermia have less impact than congenital azoospermia on ICSI results? Systematic review and meta-analysis

An electronic-based search was performed with MEDLINE bases through PubMed, Cochrane through Central, and Embase until August 2020 for the purpose of evaluating the impact of the aetiology of obstructive azoospermia on ICSI cycles. In the final analysis, there were 15 cohort studies included, comparing a group of patients with acquired azoospermia and others due to congenital bilateral absence of the vas deferens submitted to ICSI. Those 15 articles within 4,480 couples were analysed, and similar fertilisation rate (65.1% vs. 65.3%; p = .38), pregnancy rate per cycle (40.0% vs. 43.1%; p = .06) and live birth rate (29.6% vs. 30.0%;p = .76) were found between groups. Comparing specifically post-vasectomy azoospermia and congenital groups, both presented a similar fertilisation rate (62.4% vs. 53.4%, respectively; OR 1.10; 95% CI, 0.79, 1.54; p = .56; I²  = 89%) and pregnancy rate per cycle (39.4% vs. 35.6%, respectively; OR 1.26; 95% CI, 0.96, 1.66; p = .09; I²  = 0%). However, a higher live birth rate was identified in the congenital group compared to vasectomy group (28.4% × 19.5%; OR 1.54; 95% CI, 1.11, 2.15; p = .01; I²  = 0%). The reasons for that are unclear and factors such as couple age and sperm DNA fragmentation should be considered.

A comparison of the relative efficiency of ICSI and extended culture with epididymal sperm versus testicular sperm in patients with obstructive azoospermia

This is a retrospective cohort study comparing blastocyst transfer outcomes following intracytoplasmic sperm injection utilizing epididymal versus testicular sperm for men with obstructive azoospermia. All cases at a single center between 2012 and 2016 were included. Operative approach was selected at the surgeon's discretion and included microepididymal sperm aspiration or testicular sperm extraction. Blastocyst culture was exclusively utilized prior to transfer. The primary outcome was live birth rate. Secondary outcomes included fertilization rate, blastulation rate, euploidy rate, and implantation rate. A mixed effects model was performed. Seventy-six microepididymal sperm aspiration cases and 93 testicular sperm extraction cases were analyzed. The live birth rate was equivalent (48.6% vs 50.5%, P = 0.77). However, on mixed effects model, epididymal sperm resulted in a greater likelihood of fertilization (adjusted OR: 1.37, 95% CI: 1.05–1.81, P = 0.02) and produced a higher blastulation rate (adjusted OR: 1.41, 95% CI: 1.1–1.85, P = 0.01). As a result, the epididymal sperm group had more supernumerary blastocysts available (4.3 vs 3, P < 0.05). The euploidy rate was no different. Pregnancy rates were no different through the first transfer cycle. However, intracytoplasmic sperm injection following microepididymal sperm aspiration resulted in a greater number of usable blastocysts per patient. Thus, the true benefit of epididymal sperm may only be demonstrated via a comparison of cumulative pregnancy rates after multiple transfers from one cohort.

Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations

We herein summarise the evidence concerning the impact of sperm DNA fragmentation in various clinical infertility scenarios and the advances on sperm DNA fragmentation tests. The collected evidence was used to formulate 41 recommendations. Of these, 13 recommendations concern technical aspects of sperm DNA fragmentation testing, including pre‐analytical information, clinical thresholds and interpretation of results. The remaining 28 recommendations relate to indications for sperm DNA fragmentation testing and clinical management. Clinical scenarios like varicocele, unexplained infertility, idiopathic infertility, recurrent pregnancy loss, intrauterine insemination, in vitro fertilisation/intracytoplasmic sperm injection, fertility counselling for men with infertility risk factors and sperm cryopreservation have been contemplated. The bulk evidence supporting the recommendations has increased in recent years, but it is still of moderate to low quality. This guideline provides clinicians with advice on best practices in sperm DNA fragmentation testing. Also, recommendations are provided on possible management strategies to overcome infertility related to sperm DNA fragmentation, based on the best available evidence. Lastly, we identified gaps in knowledge and opportunities for research and elaborated a list of recommendations to stimulate further investigation.

Sperm Extraction in Obstructive Azoospermia: What's Next?

For men with obstructive azoospermia, several surgical sperm retrieval techniques can facilitate conception with assisted reproductive technology. The evolution of both percutaneous and open approaches to sperm retrieval has been affected by technological innovations, including the surgical microscope, in vitro fertilization, and intracytoplasmic sperm injection. Further modifications to these procedures are designed to minimize patient morbidity and increase the quality and quantity of sperm samples. Innovative technologies promise to further ameliorate outcomes by selecting the highest quality sperm. Although various approaches to surgical sperm retrieval are now well established, several advancements in sperm selection and optimization are being developed.

Extended indications for sperm retrieval: summary of current literature

Sperm retrieval combined with intracytoplasmic sperm injection (ICSI) is the treatment of choice for couples with untreatable azoospermia-related infertility. However, an increasing body of evidence has been mounting, suggesting that ICSI with testicular sperm instead of ejaculated sperm (when both are available) increases pregnancy outcomes in some specific scenarios. This has led to the exploration of extended indications for sperm retrieval. This review summarizes the current literature concerning sperm retrieval and ICSI for non-azoospermic men with elevated sperm DNA fragmentation, oligozoospermia, and cryptozoospermia.

Interventions to Prevent Sperm DNA Damage Effects on Reproduction

Excessive oxidation and antioxidant imbalance resulting from several conditions may cause sperm DNA damage, which, in turn, affect male fertility, both natural and assisted. Sperm DNA damage transferred to the embryo might also affect the health of offspring. Several conditions associated with excessive oxidative stress are modifiable by the use of specific treatments, lifestyle changes, and averting exposure to environmental/occupational toxicants. Here, we discuss the strategies to reduce sperm DNA damage with a focus on clinical and surgical interventions.

Testicular spermatozoon is superior to ejaculated spermatozoon for intracytoplasmic sperm injection to achieve pregnancy in infertile males with high sperm DNA damage

The purpose of this study was to compare the clinical outcome of testicular spermatozoon versus ejaculated spermatozoon in the treatment of infertile males with high sperm DNA damage, referred as sperm DNA fragmentation index (DFI), that attending intracytoplasmic sperm injection (ICSI) programme in terms of clinical pregnancy, births delivered as the primary and pregnancy loss and embryo fertilisation as the secondary outcome. A total of 102 males fulfilling the inclusion criteria were enrolled in the present study. Of the 102 males, 61 infertile males underwent testicular spermatozoon combined with ICSI while the remaining 41 males applied ejaculated spermatozoa in their first ICSI cycles, and the data of them were collected and analysed. In a 18-month follow-up, testicular spermatozoon achieved higher pregnancy rate and deliver rate than those in ejaculated sperm group (pregnancy rate, 36% vs. 14.6%, p = 0.017; deliver rate, 38.5% vs. 9.8%, p = 0.001). Nevertheless, there were no significant differences in the number of oocytes aspirated and number of embryos transferred between the two groups. Additionally, the fertilisation rate in the testicular sperm study cohort (70.4%) was also similar to that in the ejaculated sperm group (75.0%). Based on the current data, we conclude that testicular spermatozoon is the prior option in the treatment of infertile males with high sperm DFI in ICSI programme. More high-quality studies with larger samples size are needed in the future due to the relative small size and the nonrandomized design of the present study.